Load weighing systems for commercial vehicles, such as logging and other trucks, generally use a plurality of load cell assemblies to monitor the amount of weight loaded on the beds of the truck trailers. Each load cell assembly usually includes a machined load cell block that is supported between two load carrying members, such as log supports, and mounting members, such as a truck trailer frame. As an increasing load is placed on the trailer, the load cell blocks are subject to increasing deflections that are directly related to the load placed on the trailer.
Strain gauges applied to various locations on the load cell blocks and protected from damage by cover plates are used to determine the deflections of the load cell blocks as a trailer is loaded. The deflection data obtained from the strain gauges is then used to calculate the weight of the load placed on the trailer.
The strain gauges are connected to monitoring equipment that calculates and records the load placed on the trailer by wiring that is connected at one end to the strain gauges or other sensing elements, passes through an internal passageway in the load cell block, and is connected at the other end to an electrical connector mounted on the a side or end of the load cell block. The electrical connector on the side of end of the load cell block is in turn releasably connected to a mating electrical connector that includes a cable connected to the monitoring equipment.
Prior electrical connectors mounted on the load cell blocks are prone to a number of problems. Because load cell blocks are mounted on the exterior of trailers, they are exposed to harsh environmental elements including extreme temperature and moisture variations. When used on logging truck trailers, the load cell blocks and electrical connectors are also subject to extreme physical punishment from frequent contact with logs, tree limbs, etc.
In the past, it has been difficult, if not impossible, to maintain an environmental seal between the load cell block and the electrical connector mounted on the load cell block. Over time, moisture migrates through the seal between the load cell block and electrical connector and into the interior of the load cell block. Even small quantities of moisture in the interior of the load cell block can corrode or short out the strain gauges or electrical wiring within the load cell block. This moisture problem is magnified by movement and loosening of the electrical connector as the load cell block is placed under load or is vibrated during operation of the truck.
In addition to corrosion caused by moisture, the electrical connection between the load cell block and the mating electrical cable is prone to physical damage caused by contact with exterior objects. Sometimes, sufficient force is placed on the electrical cable or electrical connector to damage the connector or, in some cases, pull or knock the electrical connector entirely off of the load cell block. Prior electrical connectors extend outward normal to the surface of the load cell a sufficient distance to present a relatively large target that can be easily damaged.
In applications requiring a great deal of accuracy, the electrical connection between the load cell block and the cable is sometimes a source of errors in load measurements made using the load cell block. As with most releasable electrical connectors, sometimes a poor connection is established between the parts of the connector. Electrical connectors formed of multiple pans are also more prone to errors introduced by movement or vibration of the connector.
Thus, there exists a need for an electrical connector that reduces or eliminates some of the disadvantages of the prior electrical connectors used on load cell blocks. Specifically, there exists a need for an electrical connector that will reduce load cell failures caused by moisture or physical damage to the electrical connectors.